US3595254A - Lifting apparatus - Google Patents

Abstract

Lifting apparatus for a tank construction, said apparatus comprising a lifting arm shaped to conform substantially with adjacent surfaces of a bottom wall and at least one sidewall of said tank, a pivot shaft secured adjacent the upper end of said arm and passing transversely through said sidewall adjacent the upper edge thereof, and a pivot mechanism for angularly displacing said shaft, said mechanism being mounted on the outside of said tank adjacent said shaft and secured to an outer protruding end of said shaft, said arm being shaped to pass under an elongated member contained in said tank and to raise said member upon operation of said pivot mechanism to a level adjacent the top of said tank and above a level of treatment liquid contained in said tank.

Description

United States Patent inventors Ralph C. White Bethel Park; Robert N. Christian, McMurr'ay, both of, Pa. {211 App]. No. 874,268 [22] Filed Nov. 5, 1969 [45] Patented July 27, 1971 [73] Assignee The Bushnell Machinery Company Pittsburgh, Pa.

[54] LIFTING APPARATUS 13 Claims, 3 Drawing Figs.

[52] US. Cl 134/122, 134/15,134/114,134/135,134/160 [51] Int. Cl B081: 13/00 [50] Field ofSearch 134/64, 114,122,135,160, 9,15

[56] References Cited UNITED STATES PATENTS 286,538 10/1883 Hall et a].

Primary Examiner-Robert L. Bleutge Att0rneyDon .1. Smith ABSTRACT: Lifting apparatus for a tank construction, said apparatus comprising a lifting arm shaped to conform substantially with adjacent surfaces of a bottom wall and at least one sidewall of said tank, a pivot shaft secured adjacent the upper end of said arm and passing transversely through said sidewall adjacent the upper edge thereof, and a pivot mechanism for angularly displacing said shaft, said mechanism being mounted on the outside of said tank adjacent said shaft and secured to an outer protruding end of said shaft, said arm being shaped to pass under an elongated member contained in said tank and to raise said member upon operation of said pivot mechanism to a level adjacent the top of said tank and above a level of treatment liquid contained in said tank.

PATENTEUJULZYIBTI 3595254 SHEET 1 OF 2 I 50 HI M012 1 $55 O (1, and Fly, 4, 50mm A. LZr'clsda/z.

1 111112 AWTTORNEJ/P LIFTING APPARATUS The present invention relates to lifting apparatus and more particularly to novel apparatus of the character described for use in raising elongated items such as metal strip contained in elongated tanks or other containers, for example in pickling tanks and the like.

Although our invention is described primarily in connection with pickling apparatus, it will be obvious that our novel structure has other uses, particularly with respect to corrosive environments. It will also be apparent that our novel lifting apparatus can be employed in connection with conventional pickling tanks, with other tanks for handling elongated items, or with the granite tank constructions described and claimed in our copending applications entitled Pickling Apparatus, filed Feb. 20, 1968, Ser. No. 706,823, now Pat. No. 3,473,79I and Pickling Apparatus filed July 25, I969, Ser. No. 844,879.

Conventional lifting apparatus for the aforementioned applications usually include an arm extended through an opening in the cover for the pickling tank or the like into the interior of the tank. In many cases, the lifting apparatus, sometimes referred to as a strip lifter, is of such construction that considerable space must be left between the edge of the strip or other elongated article and the adjacent inner sidewall of the tank. Thus, the full width of the tank can not be occupied by the strip undergoing treatment within the tank. In pickling apparatus or in other apparatus handling corrosive materials giving rise to noxious vapors, the extension of the strip lifter arm through the tank cover presents sealing problems and possible escape of the noxious fumes to the surrounding atmosphere. As a number of these strip lifters must be employed for many types of pickling and similar tank constructions, this situation becomes aggravated.

Conventional strip-lifting apparatus usually includes a column'or standard which projects a considerable distance above the tank structure such that a minimum ceiling height is established. In many industrial environments the projecting columns interfere with operation of overhead cranes and the like. The support columns for the strip lifters, moreover, usually are mounted independently of the tank construction which causes a similar expenditure of wasted space in the lateral direction of the tank. The independent installation of the strip lifters complicates the installation of the tank construction by introducing problems of initial alignment, relative movement, maintenance, etc. In many such tank installations utilizing conventional lifting apparatus, a further problem is introduced when it is desired to completely remove the cover from the pickling tank.

In many cases the arm of the conventional strip lifter must be turned aside when not in use to prevent wearing contact with the moving strip. The structure of the conventional strip lifter is thereby complicated.

We overcome these difficulties of the prior art by providing lifting apparatus which is permanently and entirely mounted on the tank construction. Thus the need for an independent mounting of the lifting apparatus is obviated, with the additional advantage that a considerable saving in valuable manufacturing space is effected. The major portion of the lifting apparatus is contained withinthe tank construction both in the raised and lowered positions of the apparatus. As a result, use of our novel lifting apparatus permits the tank and its cover to be readily sealed against escape of noxious fumes or vapors. Similarly our lifting apparatus does not interfere with placement and removal of the tank cover. Means are provided by our invention to reduce considerably the very rapid wear to which conventional strip lifters are subject. Replacement of that portion of the strip lifter which contacts the strip is necessary, therefore, only at considerable intervals in contrast to the prior art. Those portions of our novel lifting apparatus which are passed between the edges of the strip and the adjacent wall surfaces are very thin, such that the strip can occupy substantially the full interior width of the tank construction.

Our novel lifting apparatus, moreover, owing to its excellent wearing capability, can be left at its initial lifting position in the bottom of the tank in order to simplify its construction. Finally, the potentiality of misalignment between the lifting apparatus and the tank construction or the strip contained therein is eliminated by our novel construction.

We accomplish these desirable results by providing lifting apparatus for tank construction, said apparatus comprising a lifting arm shaped to pass under an elongated member contained in said tank, means for pivoting said arm near the top of said tank and above a level of treatment liquid contained therein, and actuating means juxtaposed to said pivot means and mounted on the outer surface of said tank, said actuating means operably engaging said pivot means for moving said lifting arm between lowered and raised positions thereof.

We also desirably provide a similar lifting apparatus wherein said lifting arm is of generally U-shaped configuration conforming substantially to the adjacent surface portions of the bottom and both sidewalls of said tank.

We also desirably provide a similar lifting apparatus wherein similar pivot means and actuating means are coupled to an upper end portion of each side member of said U-shaped lifting arm.

We also desirably provide a similar lifting apparatus wherein said lifting arm includes a preloaded beam shaped for passage beneath said elongated member.

We also desirably provide a similar lifting apparatus wherein said beam is fabricated from granite and is secured to the remainder of said arm by tensioned bolt means.

We also desirably provide a similar lifting apparatus wherein said pivot means, said actuating means, and said lifting arm are positioned below cover-sealing means adjacent the upper edges of said tank.

During the foregoing discussion, various objects, features and advantages of the invention have been set forth. These and other objects, features and advantages of the invention together with structural details thereof will be elaborated upon during the forthcoming description of certain presently preferred embodiments of the invention and presently preferred methodsof practicing the same.

In the accompanying drawings we have shown certain presently preferred embodiments of the invention and have illustrated certain presently preferred methods of practicing the same, wherein:

FIG. 1 is a top plan view of a portion of a pickling tank construction or the like having our novel lifting apparatus installed thereon;

FIG. 2 is an elevational view of the apparatus as shown in FIG. 1; and

FIG. 3 is a cross-sectional view of the apparatus as shown in FIG. 1 and taken along reference line III-III thereof.

Referring now more particularly to the drawings, our lifting apparatus 20 is mounted in this example on a pickling tank 22 or similar tank construction for handling, in this example, steel strip. The tank 22 can be of conventional rubber-lined steel construction or the like, or it can be fabricated after the manner described and claimed in our aforementioned copending applications. On the other hand, the lifting apparatus 20 can be employed with other conventional tank constructions, i.e. those not employed in corrosive environments. As better shown in FIG. 3, the tank 22 in this example is formed from granite in accordance with the teachings of our aforementioned copending application and is therefore shaped such that the junctions between the sidewalls 24 and bottom wall 26 are filleted at 28.

The strip lifting apparatus 20 includes in this example, a lifting arm 30 shaped to pass under strip 94 or other elongated member and desirably to conform to the bottom 26 and at least one sidewall 24 of the tank. The lifting arm can be of U- shape, the side and bight members of which closely conform to the sides and bottom 24, 26 of the tank construction 22. In this connection, the sides of the arm 30 are relatively thin such that the strip or other elongated member passing through the U-shaped arm can be extended substantially across the inside width of the tank 22, ifdesired.

At the lower ends of the side members 32 of the arm 30 are secured fillet members 34 which in this example are rounded to conform to the fillets 28 of the tank 22. The fillets 34 are further shaped for bolting to the bight member or lift beam 36 of the arm 30 and for this purpose are provided with end walls 38. The fillet members or corner pieces 34 can be provided with side sections 40 as better shown in FIG. 1 so that in effect the corner members 34 are cup-shaped for purposes described below.

The bight member 36 in this example is fabricated from a granite beam of substantial thickness for wearability when contacted by the moving strip and for corrosion resistance where the lifting apparatus 20 is mounted on a pickling tank or the like. Each end area of the bight member 36 is at least equal to the area of each comer member and plate 38, as best shown in FIG. 2. The vertical side 42 of the granite beam 36 (H0. 2) are rounded for the purpose described below.

The side members 32 and corner members 34 of the arm structure 30 can be fabricated from steel coated with an epoxy resin for proper corrosion resistance for pickling environments.

In this example the bight member or strip-contacting beam 36 is secured to the corner members 34 by means of a pair of elongated mounting bolts 44 which are passed through longitudinal channels extending through the bight member 36 and through alignable apertures in the corner member end plates 38. Desirably the mounting bolts 44 are heated prior to bolting of the beam 36 to place the beam under longitudinal compression for preloading purposes. A suitable silicone or epoxy sealant can be used to substantially fill the comer members to protect the adjacent ends of the bolts when the lifting apparatus is employed in a corrosive environment. For the same purpose the longitudinal channels 46 extending through the bight member 36 are oversized for suitable clearances relative to the bolts 44 extending therethrough and one or more transverse holes 48 are bored transversely to the passages 46 for the purpose of forcing quantities of the aforementioned sealant into the passages 46 in order to prevent corrosion of any portion of the mounting bolts 44 extending therethrough. Desirably the aforementioned sealant is pumped into the clearances between the bolts 44 and the longitudinal passages 46 under pressure to assure complete filling of the clearances with the protective sealant.

It will be understood, of course, that other materials can be substituted for the aforementioned materials depending upon a specific application of the invention. Further it should be stated that the arm structure 30 can be simplified, for example by replacing the preloaded granite beam with a simple crossbeam of steel, in those applications not involving a corrosive environment.

Pivot means are provided to mount the lifting arm 30 on the tank and to and in angularly displacing the arm structure 30. One form of such pivot means includes a pair of pivot shafts 50 respectively secured adjacent the upper ends of the arm structure 30 and extended through horizontal passages 52 in the sidewalls 24 of the tank 22. The shafts 50 desirably are coaxially aligned with one another and rigidly secured to the arm structure 30 to form part of a pivot mechanism for the arm structure 30, which will be described presently.

The pivot shafts 50 are joined adjacent the upper ends of the lifting arm side members 32 and the shaft passages 52 are positioned adjacent the upper edges of the tank sidewalls 24 so that the strip 94 is raised near the top of the tank 22 and above the level ofa treatment liquid contained in the tank 22. Desirably the lifting arm 30 is pivoted at such location which, together with the particular shape of the bight member 36, will support the strip 94 substantially in the plane defined generally by upper edges 66 or 67 of the tank walls 24, such that the strip in its raised position does not interfere with tank cover 88, while permitting a maximum height of treatment liquid within the tank 22.

A bushing 54, which can be fabricated from Teflon, is inserted between each of the shafts 50 and its corresponding passage 52. The closely fitting bushing 54 aids in preventing the escape of hazardous liquids or fumes from the tank construction 22. In furtherance of this purpose, packing boxes 56 are secured to mounting plates 58, respectively. As shown in FIG. 3, each pivot shaft 50 projects outwardly of the associated tank wall 24 for insertion through an aperture therefor in the related mounting plate 55, and thus extends through the aforementioned packing box 56 and an associated sleeve bearing 60, positioned outwardly thereof and likewise mounted on mounting plate 58.

As better shown in FIG. 2 each mounting plate 58 includes a pair of hanging and positioning tabs 62, 64 which overly adjacent portions of the upper edge portions 66 of each sidewall 24. Each mounting plate 58 is further secured to the outer surface of the associated wall 24, in this example, by means of a number of mounting bolts 68. As noted above the mounting plate 58 is provided with a suitable aperture aligned with the packing box 56 and sleeve bearing 60 through which the associated pivot shaft 50 extends. To the protruding end of each pivot shaft 50 a crank 70 is secured for angular displacement therewith and hence with the lifting arm 30. The crank 70 is pivoted at 72 to the distal end of piston rod 74 forming part of a piston and cylinder arrangement denoted generally by reference character 76. The throw or stroke of the cylinder 76 is such that, in this example, the crank 70 is displaced through an angle of about 90. To permit the distal end of the piston rod 74 to follow the pivot 72 and the crank 70 the cylinder desirably is mounted upon a trunnion arrangement denoted generally by reference character 78. The trunnion 78 likewise is mounted upon mounting plate 58.

In this example, the trunnion 78 includes a girdling ring 80 secured to the cylinder 76 and having diametric trunnion shafts 82 rotatably mounted in sleeve bearings 84 supported on trunnion bracket 86.

With this arrangement it will be seen that the novel lifting apparatus in its entirety is mounted on the tank construction 22. The moving parts of the lifting apparatus 20 are at all times clear of tank cover 88 and therefore do not interfere with the sealing of the cover or with movement thereof. This situation attains irrespective of the particular operating position of the lifting arm 30. By mounting the components of the lifting apparatus 20 entirely on the tank 22, the installation of the tank 22 is considerably simplified, as external supporting standards and the like for the lifting apparatus are eliminated, together with the problem of independent mountings, alignment, and undesired relative movements of the tank and conventional external supports during the life of the installation. It is also apparent that our novel lifting apparatus employs a minimum of parts which further reduces the complexity of initial manufacture and subsequent maintenance.

Assembly of our lifting apparatus is considerably facilitated as the pivot mechanism therefor, including the cylinder 76, is mounted upon the mounting plates 58. For example, the lifting structure can be removed from the tank construction 22 with relative ease by disconnecting the lifting arm 30 from its pair of pivot shafts 50, and withdrawing the mounting plates together with the shafts 50 and the lifting arm actuating means or pivot mechanisms secured to the mounting plates, after removing bolts 68. The lifting arm 30 can then be removed from the interior of the tank 22 after removing cover 88. If it is not desired to remove the lifting arm 30, the cranks 70 can be disconnected from the outer ends of the pivot shafts 50, whereby the mounting plates 58 and the components secured thereto can be removed as unitary structures. Our lifting apparatus therefore can be readily assembled and disassembled to facilitate original installation and subsequent maintenance.

It will be apparent therefore that the lifting arm 30, the pivot means 50, and the actuating means 76 including the mounting plate 58 therefor are positioned substantially below the tank cover 88. The tank cover therefore can be sealed by suitable means to the inward upper edges 67 of the tank construction 22 without interference from the operating components of the lifting apparatus 20. One form of such sealing means includes water trough 89 formed in the tank edges 67 and cooperating with a depending flange 91 formed about the periphery of the cover 88, as described and claimed in our first-mentioned copending application. A sealing strip 93 can be employed to support the cover 88 on the tank edges 67. When utilizing the water seal 89-91, it is important that the pivot means 50 of the lifting arm 30 be extended through aperture means adjacent but below the water trough 89, for maximum lifting height of the arm 30.

ln operation, the lifting apparatus when not in use is positioned as shown in the solid outlines of the several figures, with a strip or other elongated member moving through a treatment liquid contained in the tank 22. As noted above, the strip can pass closely between the side members 32 of the lifting arm and hence fairly close to the sidewalls 24 of the tank 22. When it is desired to lift the strip 94 from the tank 22, for example to prevent undue reaction with a pickling solution contained in the tank, when movement of the strip is halted, the cylinders 76 are energized to displace the cranks 70 to their chain-outlined positions such as denoted by chain-outline 90 of FIG. 2. This movement, of course, angularly displaces the lifting arm 30 from its solid outline positions as shown in F IGS. 2 and 3 to its chain-outlined position 92 carrying with it the strip or other elongated member. To prevent scuffing of the strip the adjacent surface 42 of the lifting member or beam 36 is rounded and desirably polished. The opposite surface of the beam 36 can be similarly rounded for reversability to minimize replacement of the beam 36 or of the lifting arm 30. From FIG. 2 it will be observed that lifting of the strip 94 is accomplished without interference by or with the tank cover 88. 5

Depending upon the loadings involved, e.g. width, material, and thickness of the strip 94, one of the actuating cylinders 76 can be omitted depending upon the application of the invention. In the illustrated application, however, a considerable loading is imposed upon the bight member 36 when the strip is lifted and each pivot shaft 50 thereof desirably is driven as shown. Moreover, the use of duplicate pivot mechanisms applies a balanced torque to the lifting arm 30 for smoother operation, longer life of bearings, and reduced maintenance.

To lower the lifting arm 30, the cylinder 76 is deenergized whereupon the weight of the lifting ann returns the arm to its solid outline position, as shown in the drawings.

From the foregoing it will be apparent that novel and efficient forms of lifting apparatus have been described herein. While we have shown and described certain presently preferred embodiments of the invention and have illustrated presently preferred methods of practicing the same, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced with the spirit and scope of our invention.

We claim: t

1. Lifting apparatus for a tank construction, said apparatus comprising a lifting arm shaped to conform substantially with adjacent surfaces of a bottom wall and at least one sidewall of said tank, pivot means secured adjacent the upper end of said arm and passing transversely through said sidewall adjacent the upper edge thereof, and actuating means for angularly displacing said shaft, said actuating means being mounted on the outside of said tank adjacent said pivot means and secured to an outer protruding end of said pivot means, said arm being shaped to pass under an elongated member contained in said tank and to raise said member upon operation of said actuating means to a level near the top of said tank and above a level of treatment liquid contained in said tank.

2. The combination according to claim 1 wherein said lifting arm is angularly displaced by said actuating means such that said strip is supported in its raised position adjacent the top edges of said tank.

3. The combination according to claim 1 wherein said lifting arm is of generall U-shaped configuration conforming substantially to the a acent surface portions of the bottom and both sidewalls of said tank.

4. The combination according to claim 3 wherein similar pivot means and actuating means are coupled to an upper end portion of each side member of said U-shaped lifting arm.

5. The combination according to claim 3 wherein said lifting arm includes a preloaded beam shaped for passage beneath said elongated member.

6. The combination according to claim 5 wherein said beam is fabricated from granite and is secured to the remainder of said arm by tensioned bolt means.

7. The combination according to claim 6 wherein side members of the U-shaped arm terminate at their lower ends in cup shaped supports bolted to said beam and substantially filled with sealant to prevent corrosion of the adjacent ends of said bolt means.

8. The combination according to claim 5 wherein said beam is preloaded by bolt means extended through oversized longitudinal passage means in said beam, and transverse passages communicate with said longitudinal passage means for the introduction of sealant material into the clearances between said bolt means and said passage means.

9. The combination according to claim 7 wherein the junctions between said side and bottom tank walls are filleted, and said cup-shaped members are rounded to conform with said filleted junctions.

10. The combination according to claim 1 wherein said actuating means are positioned on a mounting plate therefore having an aperture therein for receiving said pivot means, said plate including a pair of positioning tabs overlying an adjacent upper edge of said tank.

11. The combination according to claim 10 wherein said actuating means further include a piston and cylinder arrangement trunnion-mounted on said mounting plate and connected to said pivot means through a crank.

12. The combination according to claim 1 wherein said pivot means, said actuating means, and said lifting arm are positioned below cover sealing means adjacent the upper edges of said tank.

13. The combination according to claim 12 wherein said sealing means include a water trough formed in said upper edges, said pivoting means extending through aperture means therefor in said sidewall adjacent but below said sealing trough.

Claims (13)

1. Lifting apparatus for a tank construction, said apparatus comprising a lifting arm shaped to conform substantially with adjacent surfaces of a bottom wall and at least one sidewall of said tank, pivot means secured adjacent the upper end of said arm and passing transversely through said sidewall adjacent the upper edge thereof, and actuating means for angularly displacing said shaft, said actuating means being mounted on the outside of said tank adjacent said pivot means and secured to an outer protruding end of said pivot means, said arm being shaped to pass under an elongated member contained in said tank and to raise said member upon operation of said actuating means to a level near the top of said tank and above a level of treatment liquid contained in said tank.

2. The combination according to claim 1 wherein said lifting arm is angularly displaced by said actuating means such that said strip is supported in its raised position adjacent the top edges of said tank.

3. The combination according to claim 1 wherein said lifting arm is of generally U-shaped configuration conforming substantially to the adjacent surface portions of the bottom and both sidewalls of said tank.

4. The combination according to claim 3 wherein similar pivot means and actuating means are coupled to an upper end portion of each side member of said U-shaped lifting arm.

5. The combination according to claim 3 wherein said lifting arm includes a preloaded beam shaped for passage beneath said elongated member.

6. The combination according to claim 5 wherein said beam is fabricated from granite and is secured to the remainder of said arm by tensioned bolt means.

7. The combination according to claim 6 wherein side members of the U-shaped arm terminate at their lower ends in cup-shaped supports bolted to said beam and substantially filled with sealant to prevent corrosion of the adjacent ends of said bolt means.

8. The combination according to claim 5 wherein said beam is preloaded by bolt means extended through oversized longitudinal passage means in said beam, and transverse passages communicate with said longitudinal passage means for the introduction of sealant material into the clearances between said bolt means and said passage means.

9. The combination according to claim 7 wherein the junctions between said side and bottom tank walls are filleted, and said cup-shaped members are rounded to conform with said filleted junctions.

10. The combination according to claim 1 wherein said actuating means are positioned on a mounting plate therefore having an aperture therein for receiving said pivot means, said plate including a pair of positioning tabs overlying an adjacent upper edge of said tank.

11. The combination according to claim 10 wherein said actuating means further include a piston and cylinder arrangement trunnion-mounted on said mounting plate and connected to said pivot means through a crank.

12. The combination according to claim 1 wherein said pivot means, said actuating means, and said lifting arm are positioned below cover sealing means adjacent the upper edges of said tank.

13. The combination according to claim 12 wherein said sealing means include a water trough formed in said upper edges, said pivoting means extending through aperture means therefor in said sidewall adjacent but below said sealing trough.

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